Fuel injection device for diesel engines



April 4, 1950 E. RATHBUN FUEL INJECTION DEVICE FOR DIESEL ENGINES 2Sheets-Sheet 1 Filed March 5, 1945 NOZZLES GOVERNOR IN VEN TOR. E DWHEDEHTHBUN April 9 1950 E. RATHBUN 2,502,989

FUEL INJECTION DEVICE FOR DIESEL ENGINES Filed March 5, 1945 2Sheets-Sheet 2 a 16 P 77 l i i 17 19/ i 21 L J5 I 11.. hi

INVENTOR.

A TTORNEY Patented Apr. 4, 1950 FUEL INJECTION DEVICE FOR DIESEL EN GINEdward Rathbun, Toledo, Ohio, assignor to The Rathbun-Jones EngineeringCompany, Toledo, Ohio, a corporation of Ohio Application March 5, 1945,Serial No. 581,118

3 Claims.

This invention relates to Diesel engines but more particularly to fuelinjection systems for such engines.

High compression internal combustion engines which are adapted to employeither oil or gas or a mixture of the two fuels are equipped with agovernor controlling the rate of fuel supply in accordance with thedemands of service and the availability of the kind of fuel. In casegas, such as producer gas, is used as fuel, oil serves as an igniter, asis readily understood. It is desirable, therefore, that a substantiallyconstant minimum quantity of oil be injected for pilot ignition withoutcontrol of the governor but any quantity greater than the minimum up tothe full capacity of the injector pump be under the control of thegovernor.

An object is to produce a simple and eflicient fuel injection system ofthe above type which employs a single injection pump operating incooperation with a suitable governor mechanism.

Other objects and advantages will hereinafter appear, and for purposesof illustration but not of limitation, the invention is shown on theaccompanying drawings in which Figure 1 is a diagrammatic sectional viewshowing a fuel injection pump for a high compression internal combustionengine, fuel lines leading to the governor for the engine, a fuel lineto the injection nozzles for the engine, and

a fuel line from the fuel reservoir;

Figure 2 is a view similar to Figure 1 and showing the plunger in itsupward movement and at the point where fuel is being injected into theline leading to the fuel injection nozzles; and

Figure 3 is a schematic view showing the fuel injection pump in relationto other elements of the engine feed system.

The illustrated embodiment of the invention comprises a suitable housingor casing I0 which is provided with a pump cylinder II in which isreciprocable a piston-type plunger or pumping element I2. Leading intothe upper end of the cylinder is a passage l3 extending from a fuel oilreservoir R and controlled by a poppet type valve H which unseats -upondownward movement of the plunger to admit oil to the cylinder II. Alsoleading from the upper end of the cylinder I I is a passage I5 whichleads to the fuel injection nozzles 29 in a high compression internalcombustion engine. The passage I5 is controlled by a poppet type valveI6 which opens inwardly into the passage I5 upon upward movement of theplunger I 2 and after a predetermined pressure within the pump cylinderhas been I Cl. 123140) created. Ordinarily springs are associated withthe valves I4 and I6 to hold them normally seated as will be readilyunderstood by those skilled in this art.

Near the upper end of the cylinder I I extends a lateral passage Ilwhich leads to the governor G. It will be understood that the governormay be of the well-known type to control the amount of gas, such asproducer gas, and oil delivered to the engine cylinders in accordancewith the demands of service, as well as the available supply of gas.Governors of this type are well-known to those skilled in this art anddetail description and illustration thereof is not considered necessaryhere. A suitable governor which is wellknown in this industry and is notinfrequently employed in connection with engines of this type is knownas Type U. G. 8 Governor and manufactured by Woodward Governor Companyof Rockford, Illinois.

Spaced a short distance below the passage I1 is a passage I8 which isparallel to the passage I1 and communicates therewith at its outer endthrough a branch I9. It will be understood that reciprocatory motion isimparted to the plunger I2 in any suitable manner and as shown, itcomprises a cylindrical body portion 20 .and a head portion 2| which areintegrally connected by a reduced neck portion 22. As shown, the topsurface 23 of the head and the under or bottom surface 24 of the headare inclined or angularly disposed but in parallel relationship.Likewise the upper surface 25 of the body portion 20 is similarlyinclined and parallel to the surfaces 23 and 24.

Drilled through the head 2| is a passage 26 which terminates in alateral passage 21 opening from the neck portion 22 and into the spacebetween the surfaces 24 and 25. This enables oil from above the plungerhead 2| to pass into the space around the neck portion 22 as willhereinafter appear.

It will be understood that the distance between the heads 23 and 24 isslightly greater than the distance between the ports leading to thepassages I1 and I8 so that these passages may be covered and still aslight additional movement of the plunger may take place before thesurface 24 of the head 2| uncovers the port leading to the passage l8during the upward movement of the plunger. This additional movement isindicated by the reference numeral 28.

In operation it will be understood that when the plunger I2 movesdownwardly, the valve I4 is unseated and oil from the reservoir Rflowing 3 through the passage It enters the cylinder ll above theplunger head. when the plunger moves upwardly, oil thus drawn into thecylinder is forced therefrom through the passages It, I! and I1 assumingthat the governor calls for oil, the oil passing through the governor Gbeing returned to the reservoir R through the communicating passage llb.However, since the plunger head 2| closes oil the passages I 'I' and I8,the additional movement of the plunger indicated by the reference number28 enables oil disposed above the plunger head to be forced past thevalve 16 and into the passage l5 to the injection nozzles 29 of theengine represented in Figure 3 by a cylinder C having a piston P, and

its piston rod R reciprocal therein, it being the governor G. However,the timing of the injection of oil to the nozzle passage may be variedby rotatively adjusting the plunger l2 in connection with the structuresuch as illustrated. Any quantity of oil above such minimum iscontrolled by the operation of the governor depending upon whether thegovernor calls for a greater or lesser quantity of oil. By making theupper surface .of the plunger straight across instead of angularlydisposed, as shown, the timing of the injection of oil to the nozzlepassage ll is controlled by the point in the plunger travel at which thepassage I1 is covered assuming that the passages leading to the governorare substantially unrestricted, and would not change when the plungerLs, rotatively adjusted. Howunderstood that such force created issumcient-- to unseat the valve it against the force of the spring (notshown) which is associated there with.

Thus it will be understood that this additional movement 28 afiords aminimum and substantially fixed quantity of oil to the engine as, forexample, for pilot ignition in the case of an oilgas engine. It will bemanifest that such minimum quantity is not controlled by the governorbut in the event that the governor does not call for oil so that thepump I2 can not force oil from the cylinder through the passages l8, l9and I1, then all of the oil within the cylinder will be forced to thenozzles 29 through the passage i5.

Furthermore, if the governor calls for a reduced amount of oil, then theadditional oil over and above that called for by the governor will bedelivered to the nozzles through the passage 15 as will be readilyunderstood. Thus although the minimum quantity of oil delivered to thenozzles is not controlled by the governor, the governor does control anyquantity greater than that minimum up the maximum capacity of the pump.

By angularly disposing the surfaces 23 and 24 of the plunger head 2|,the plunger l2 may be rotatively adjusted for eilfectlng operationalchanges. Such rotative adjustment may be effected manually orautomatically by suitable connection to the governor mechanism. It willbe manifest that the time at which injection starts will be changed,that is, the time at which oil is forced from the cylinder ll into thepassage l5. By maintaining the surfaces or faces 23 and 24 in parallelrelationship, the amount of oil re-,-

in parallel relationship, then the rotative adjustment of the plunger l2will affect both the quantity of oil delivered to the nozzles as well asthe timing of such delivery. For example, if'the surface 23 weredisposed at'right angles to the axis of the cylinder H, the timing ofthe fuel in the plunger travel at which the p SSage I1 is covered anddoes not change when the plunger is rotatively adjusted, although thequantity is changed depending upon the angularity of the face or surface24.

From the above description it will be apparent that the minimum quantityof oil delivered to the. nozzles 29 through the passage 15 remains ever,in such event, the quantity of oil delivered to the nozzle passage II isdependent upon the angularity of the face 24 or the degree of rotativeadjustment given the plunger l2.

It is to be understood that numerous changes in details of construction,arrangement and operation may be effected without departing from thespirit of the invention especially as defined in the appended claims.

What I claim is:

1. In a Diesel engine having a fuel controlling governor and oilinjection nozzles, means providing a pump cylinder, oil supply passageleading to the head end of said pump cylinder, a passage also in thehead end of said cylinder end leading to the oil injection nozzles,valves controlling said passages respectively, a passage leading from aside of said cylinder to the governor, a branch passage communicatingwith said governor passage and spaced inwardly therefrom and leadingfrom the side of said cylinder, a reciprocatory pump plunger within saidcylinder having a body, a reduced neck and a head portion, the length ofsaid head being uniform throughout and being slightly greater than thedistance between said governor passages, and a passage extending fromthe outer end of said plunger head, centrally therethrough and open inginto said neck portion, whereby in the reciprocation of the plunger theminimum quantity of oil delivered to the nozzles is maintained constant.

2. ,A fuel injection system as claimed in claim 1, in which the plungeris rotatable, and the inner and outer faces or surfaces of the plungerhead extend circumferentially thereof, are inclined and disposed inparallel relation, thereby to vary the timing of the injection of pilotoil to the nozzles during plunger movement of the head during the periodwhen both governor passages are covered.

3. In a Diesel engine having a fuel controlling governor, meansproviding a pump cylinder, passage means extending laterally of theouter end portion of the cylinder and adapted to communicate with thegovernor, valve controlled passages 2 adjacent and head end of thecylinder and ar- .2 injection to the passage I5 is fixed by the point"franged outwardly of said passage means and adapted to communicaterespectively with the 4 fuel oil supply and the engine injectionnozzles,

{a rotatively adjustable plunger reciprocable in .the cylinder, a headon the plunger movable to cover said passage means, opposite faces ofsaid 'head being parallel and inclined relative to the axis of theplunger, the length of said head throughout being such that the same ismovable during the period that the said passage means -.is covered, anda passage extending centrally constant and is not aflected by theoperation of 16' through the plunger for enabling liquid at the outerend or said head to flow to the inner side thereof after the inner; endof said head has uncovered said passage means, whereby in thereciprocation of the pump plunger the minimum quantity of oil deliveredto the nozzles is maintained constant but the timing of oil injection isvaried in response to rotative adjustment or the plunger.

EDWARD RATHBUN;

REFERENCES CITED The following references are of record in the file ofthis patent:

6 UNITED STATES PATENTS Number 1,883,265 1,883,980

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